D3 Block-a-Day: Day 6, January 6th, 2017

D3 Block-a-Day: Day 6, January, 6th 2017

New Year's Resolution for 2017: Make a D3 Block a day to teach myself D3. This is Number 6. This example is my first map example and shamelessly copies a neat example by Michelle Chandra. This example tweaks some of the tooltip stylings but keeps everything else pretty much the same.

<!DOCTYPE html>
<meta charset="utf-8">
<head>
<title>D3 Block-a-Day: Day 6, January 6, 2017</title>
<script src="https://d3js.org/d3.v4.min.js"></script>
<style type="text/css">

/* On mouse hover, lighten state color */
path:hover {
	fill-opacity: .8;
}

/* Style for Custom Tooltip */
div.tooltip {
 	position: absolute;
	text-align: center;
	width: 80px;
	padding: 7px;
	font: 12px Helvetica Neue;
	background: #fff8dc;
  border: 2px solid;
  border-color: black;
	border-radius: 3px;
	pointer-events: none;
  box-shadow: rgba(0, 0, 0, 0.3) 0 2px 10px;
}

/* Legend Font Style */
body {
	font: 11px Helvetica Neue;
}

/* Legend Position Style */
.legend {
	position:absolute;
	left:800px;
	top:350px;
}

</style>
</head>
<body>
<script type="text/javascript">

/*  This visualization was made possible by modifying code provided by:

Michelle Chandra’s Block 0b2ce4923dc9b5809922
https://gist.github.com/michellechandra/0b2ce4923dc9b5809922 */

//Width and height of map
var width = 960;
var height = 500;

// D3 Projection
var projection = d3.geoAlbersUsa()
				   .translate([width/2, height/2])    // translate to center of screen
				   .scale([1000]);          // scale things down so see entire US

// Define path generator
var path = d3.geoPath()               // path generator that will convert GeoJSON to SVG paths
		  	 .projection(projection);  // tell path generator to use albersUsa projection

// Define linear scale for output
var color = d3.scaleLinear()
			  .range(["rgb(213,222,217)","rgb(69,173,168)","rgb(84,36,55)","rgb(217,91,67)"]);

var legendText = ["Cities Lived", "States Lived", "States Visited", "Nada"];

//Create SVG element and append map to the SVG
var svg = d3.select("body")
			.append("svg")
			.attr("width", width)
			.attr("height", height);

// Append Div for tooltip to SVG
var div = d3.select("body")
		    .append("div")
    		.attr("class", "tooltip")
    		.style("opacity", 0);

// Load in my states data!
d3.csv("states-lived.csv", function(data) {
color.domain([0,1,2,3]); // setting the range of the input data

// Load GeoJSON data and merge with states data
d3.json("us-states.json", function(json) {

// Loop through each state data value in the .csv file
for (var i = 0; i < data.length; i++) {

// Grab State Name
	var dataState = data[i].state;

// Grab data value
	var dataValue = data[i].visited;

// Find the corresponding state inside the GeoJSON
	for (var j = 0; j < json.features.length; j++)  {
		var jsonState = json.features[j].properties.name;

if (dataState == jsonState) {

// Copy the data value into the JSON
		json.features[j].properties.visited = dataValue;

// Stop looking through the JSON
		break;
		}
	}
}

// Bind the data to the SVG and create one path per GeoJSON feature
svg.selectAll("path")
	.data(json.features)
	.enter()
	.append("path")
	.attr("d", path)
	.style("stroke", "#fff")
	.style("stroke-width", "1")
	.style("fill", function(d) {

// Get data value
	var value = d.properties.visited;

if (value) {
	//If value exists…
	return color(value);
	} else {
	//If value is undefined…
	return "rgb(213,222,217)";
	}
});

// Map the cities I have lived in!
d3.csv("cities-lived.csv", function(data) {

svg.selectAll("circle")
	.data(data)
	.enter()
	.append("circle")
	.attr("cx", function(d) {
		return projection([d.lon, d.lat])[0];
	})
	.attr("cy", function(d) {
		return projection([d.lon, d.lat])[1];
	})
	.attr("r", function(d) {
		return Math.sqrt(d.years) * 3;
	})
		.style("fill", "rgb(217,91,67)")
		.style("opacity", 0.85)
		.style("stroke", "#fff")
		.style("stroke-width", "1")

// Modification of custom tooltip code provided by Malcolm Maclean, "D3 Tips and Tricks"
	// https://www.d3noob.org/2013/01/adding-tooltips-to-d3js-graph.html
	.on("mouseover", function(d) {
    	div.transition()
      	   .duration(200)
           .style("opacity", .9);
           div.text(d.place)
           .style("left", (d3.event.pageX + 10) + "px")
           .style("top", (d3.event.pageY - 30) + "px");
	})

// fade out tooltip on mouse out
    .on("mouseout", function(d) {
        div.transition()
           .duration(500)
           .style("opacity", 0);
    });
});

// Modified Legend Code from Mike Bostock: https://bl.ocks.org/mbostock/3888852
var legend = d3.select("body").append("svg")
      			.attr("class", "legend")
     			.attr("width", 140)
    			.attr("height", 200)
   				.selectAll("g")
   				.data(color.domain().slice().reverse())
   				.enter()
   				.append("g")
     			.attr("transform", function(d, i) { return "translate(0," + i * 20 + ")"; });

legend.append("rect")
   		  .attr("width", 18)
   		  .attr("height", 18)
   		  .style("fill", color);

legend.append("text")
  		  .data(legendText)
      	  .attr("x", 24)
      	  .attr("y", 9)
      	  .attr("dy", ".35em")
      	  .text(function(d) { return d; });
	});

});
</script>
</body>
</html>

Modified http://d3js.org/d3.v4.min.js to a secure url

https://d3js.org/d3.v4.min.js